Thanks guys. Unfortunately no before pics... I wasn't sure it would turn out like this . As for the technique, I used 4 different color spray paints (Ivory, Khaki, Black and Terra Cotta). I started with a base of Ivory and Khaki and then layered on the Black and Terra Cotta until it looked like stone.
The original look before I painted it looked like it was brush painted and it had a gloss finish to it. It didn't look like stone at all. It's a pretty decent sculpt of the tablet, though I might make the edges sharper and more "broken off".
PHArch - I am sure you can do just as good of a job with one of these! It was fun and looks pretty cool next to my Grail Diary. Next, is to get the Holy Grail Cup...